UN Flexible Intermediate Bulk Containers (FIBCs) used for dangerous goods must pass the applicable design-type performance tests. These tests help determine whether the bag body and lifting devices can withstand the loads encountered during transportation, stacking and handling.

Section 6.5.6 of the UN Model Regulations outlines six key tests for flexible IBCs:

1. Top Lift Test

Applies to flexible IBCs designed for top or side lifting. The bag is filled with representative material, loaded to six times its maximum permissible gross mass, lifted clear of the ground and held for five minutes.

2. Stacking Test

Applies only to IBCs designed for stacking. The test load is 1.8 times the combined maximum permissible gross mass of the similar IBCs allowed to be stacked above the test unit during transport. For flexible IBCs, the load is maintained for at least 24 hours.

3. Drop Test

Applies to all flexible IBCs. The bag must reach its maximum permissible gross mass, with the contents evenly distributed. Drop heights are 1.8 m for Packing Group I, 1.2 m for Group II and 0.8 m for Group III.

4. Tear Test

Applies to all flexible IBCs. The bag is filled to at least 95% of its capacity and its maximum permissible gross mass. A 100 mm cut is made in the bag wall at a 45° angle to the principal axis. A load equivalent to twice the maximum permissible gross mass is then applied for at least five minutes. The cut must not extend by more than 25% of its original length.

5. Topple Test

Applies to all flexible IBCs. The bag is filled to at least 95% of its capacity and its maximum permissible gross mass, then toppled from the specified height: 1.8 m for Packing Group I, 1.2 m for Group II and 0.8 m for Group III.

6. Righting Test

Applies to flexible IBCs designed for top or side lifting. The bag is placed on its side and lifted at a speed of at least 0.1 m/s until it returns to an upright position and is clear of the ground.

Each test has its own scope and acceptance criteria. In general, the bag body and lifting devices must not sustain damage that makes the FIBC unsafe for transport or handling, and unacceptable loss of contents must not occur.

Reference: UN Model Regulations, Part 6, Section 6.5.6.